Intermetallic compound materials

ABSTRACT

An intermetallic compound material, which may be produced by standard vacuum melting techniques, comprises two principal groups of constituents of which a first group includes nickel and at least one of the elements chromium, cobalt, molybdenum and tungsten within the range 72 to 83 atomic per cent, and the second group includes aluminium in combination with at least one of the elements titanium, niobium and tantalum, the material containing the constituents in the proportions, by atomic percentage, FIRST GROUP OF CONSTITUENTS 72 TO 83 SECOND GROUP OF CONSTITUENTS 17 TO 28 One preferred composition of the intermetallic compound material contains elements of the said first and second groups in the following ranges specified below, in atomic per cent,   The intermetallic compound material may contain carbon, boron, and zirconium as trace elements.

United States Patent [1 1 Restall et a1.

[4 1 Sept. 2, 1975 1 INTERMETALLIC COMPOUND MATERIALS [75] Inventors:James Edward Restall, Camberley;

Michael James Douglas Weaver, Fleet, both of England [73] Assignee:National Research Development Corporation, London, England [22] Filed:May 23, 1972 [2]] Appl. No.: 256,026

3,653,987 4/1972 Boesch 75/171 3,677,835 7/1972 Tien ct a1 75/1713,767,479 10/1973 Tarshis 75/171 Primary Examiner-R. Dean Attorney,Agent, or Firm-Cushman, Darby & Cushman [57] ABSTRACT An intermetalliccompound material, which may be produced by standard vacuum meltingtechniques, comprises two principal groups of constituents of which afirst group includes nickel and at least one of the elements chromium,cobalt, molybdenum and tungsten within the range 72 to 83 atomic percent, and the second group includes aluminium in combination with atleast one of the elements titanium, niobium and tantalum, the materialcontaining the constituents in the proportions, by atomic percentage,

first group of constituents 72 to 83 second group of constituents 17 to28 One preferred composition of the intermetallic compound materialcontains elements of the said first and second groups in the followingranges specified below, in atomic per cent,

Nickel 60 to 80 Aluminium 12 to 26 Chromium 2 to 6 Titanium 0 to 12Cobalt 0 to 12 Niobium O to 6 Molybdenum O to 3 Tantalum to 6 Tungsten(l to 3 The intermetallic compound material may contain carbon, boron,and zirconium as trace elements.

10 Claims, No Drawings INTERMETALLIC COMPOUND MATERIALS This inventionrelates to intermetallic compound ma- 2 melt is fully degassed. chromiumand any refractory metals are added under partial pressure of argon.Aluminum, titanium and zirconium are then added under vacuum and themetal cast into ingot form. Conterials and in particular to metal alloyshaving a base of 5 vcntional casting techniques have produced materialstri-nickel aluminide (Ni Al). having acceptable high temperaturestrengths and due- The majority of high temperature structuralcompotilities. Unidirectional solidification in which a tempernentscurrently used in gas turbine aero engines are ature gradient is inducedby progressive cooling in made from nickel-base alloys strengthenedprimarily by order to control crystalline growth to give a columnar theprecipitation of Ni Al (gamma-prime) throughout [0 structure has beenfound to give increased strengthand the nickel (gamma) matrix. Duringrecent years. the ductility. strengths of such alloys have been improvedby inereas- The accompanying Table I gives the compositions of ing thestability and volume fraction of the gammaseveral examples ofintermetallic compound materials prime precipitate through theintroduction of relatively according to the invention. Thesecompositions are large quantities of elements such as tungsten,molybderepresentative of those believed to give good combinanum,tantalum. niobium and titanium. This has intions of desirableproperties, but are not'intended to be volved reduction of the nickeland chromium content, exclusive.

' TABLET Alloy compositions Alloy Group A Group B Code Cr Co Ni Mo w AlTi Nb Ta C B Zr R1 3.7 6.9 64.7 1.3 17.2 5.9 0.2 0.05 0.05 R3 3.3 7.164.2 0.8 0.4 19.0 2.3 1.3 1.3 0.2 0.05 0.05 R6 3.2 7.3 62.8 0.7 0.4 20.21.1. 2.1 1.9 0.2 0.05. 005 R9 3.4 7.2 645 0.7 0.5 111.0 3.7 0.21 0.9 0.20.05 0.05 A33 5.1 7.9 61.5 1.11 19.9 3.5 0.2 0.05 0.05 A53 2.8 6.5 62.91.0 21.1 5.4 0.2 0.05 0.05 A60 3.2 6.8 64.8 1.1 19.0 4.3 0.2 0.05 0.05,A92 4.0 I 10 5 60.7 0 1 13.7 10.7. 0.2 0.05 005 A203 4.0 71.6 1.1 18.92.1 2.0 0.2 0.05 0.05 V197 3.9 7.1 64.6 1.0 19.5 3.6 0.2 0.05 0.05 V1993.5 7.1 70.0: 0.9 16.5 3.6 0.25 0.10 0.05

the strength improvements thus being obtained at the expense ofcorrosion resistance. It is known that in addition to its precipitationstrengthening role, the gam- 35 ma-prime phase present in commercialprecipitationhardened nickel-base alloys has good corrosion resistanceat high temperatures. 5 I Y Binary Ni Al has little worthwhile hightemperature Y'Testson the y- V197 Show density to be strength and isfairly brittle but alloys based on Nig Al 40 g/cc and a-meltmg pomt 1ntheregion of l30()C. Tacontaining additional alloying elements cancombine bles 1 and W Show respectively tensile, cr p pthe high corrosionresistance of Ni Al with the strength ture and oxld-atlon res1stancepropert1es. The we1ght and ductilities of modern precipitation-hardenedniek- 108565 o mm rcl llyvavallable cast and Wrought nickel-base alloysat higher temperatures than the latter can 1- alloy are cluded In TableIV for comparlson. i h Tests on the alloy V199 show its density to be8.6 An intermetallic compound material according to the g/ with aSimilar melting Point to V197- Its tensile invention comprises twoprincipal groups of constitund ep/ pture prop rties are Shown in TablesV ents of which one group includes nickel and one or and VIrespectlvelymore of the elements chromium, cobalt, molybdenum TABLE 1]and tungsten within the range 72 to 83 atomic per cent, T V197 and thesecond group includes aluminium and one or properties ijnidirecfionanymore of the elements titanium, n1ob1um and tantalum Test conventionallycast solidified temper- UTS (tsi) 71 elong- UTS (tsi) "/1 elongw1th1nthe range 17 to 2 8 atomlc per cent. I mum mm min Preferably theconst1tuents are m the followmg 20C 50 3 56 7 ranges (spec1fied 1natom1c per cent). 700C 63 3 7 8 Nickel to 80 Aluminium 12 to 26 Chromium2 to 6 Titanium 0 to 12 Cobalt O to 12 Niobium O to 6 TABLE "IMolybdenum O to 3 Tantalum 0 to 6 Tungsten O to 3 3 6O Creep ruptureproperties (V197) Unidirectionally Conventionally cast solidifiedAdditional trace elements are 0.05 to 0.5 carbon, st nditions ife Iliife q i 0.01 to 0.1 boron, and 0.01 to 0.2 zirconium (all i r) e r) iccenm es 19 151 900C 37 27 atom g d t l I din to the 8 mi 1000C 17 8 5065 lntermeta 1c compoun ma er1a s accor g 2 Si 50C 9 5 44 50 inventioncan be produced by standard vacuum meltlng 6 tsi 1000C 14 techniques. Asa typical example, nickel, cobalt. carbon and boron are melted undervacuum and when the TABLE IV Oxidation resistance Loss in weightMaterial and condition after 200 hr I250C (mg/cm) V197 As cast 3 Coated1 Commercial cast nickel base alloy coated Commercial wrought nickelbase alloy coated TABLE V Tensile properties (V l 99) UnidirectionallyTcmpersolidified Convention-ally cast ature C UTS (tsi) l1 clong- UTS(tsi) I: elongation ation TABLE VI Creep rupture properties (V 199)Unidirectionally C onvcntionally cast solidified Test conditions LifeLife (hr) "/1 elongation (hr) 1 elongation 4 tsi 1 100C 8 I3 70 30 2 [Si1 150C 10 5 261 30 6 tsi 1000C 70 2 l5 tsi 900C 140 2 1. Anintermetallic compound material composed of in atomic percent. about64.7 nickel. 3.7 chromium. 6.9 cobalt, 1.3 molybdenum. 17.2 aluminum,5.9 titanium, 0.2 carbon. 0.05 boron, and 0.05 zirconium.

2. An intermctallic compound material composed of in atomic percent,about 64.2 nickel. 3.3 chromium. 7.1 cobalt, 0.8 molybdenum. 0.4tungsten, 19.0 aluminum, 2.3 titanium, l.3 niobium, 1.3 tantalum, 0.2carbon, 0.05 boron, and 0.05 zirconium.

3. An intermetallic compound material composed of in atomic percent,about 62.8 nickel, 3.2 chromium, 7.3 cobalt. 0.7 molybdenum, 0.4tungsten, 20.2 aluminum, 1.1 titanium, 2.1 niobium, 1.9 tantalum, 0.2carbon, 0.05 boron. and 0.05 zirconium.

4. An intermetallic compound material composed of in atomic percent,about 64.5 nickel, 3.4 chromium, 7.2 cobalt, 0.7 molybdenum, 0.5tungsten, 18.0 aluminum, 3.7 titanium, 0.8 niobium, 0.9 tantalum, 0.2carbon, 0.05 boron, and 0.05 zirconium.

5. An intermetallic compound material composed of in atomic percent,about 61.5 nickel, 5.1 chromium, 7.9 cobalt, 1.8 tungsten, 19.9aluminum, 3.5 tantalum, 02 carbon, 0.05 boron, and 0.05 zirconium.

6. An intermetallic compound material composed of in atomic percent,about 62.9 nickel, 2.8 chromium, 6.5 cobalt, 1.0 molybdenum, 21.1aluminum, 5.4 tantalum, 0.2 carbon, 0.05 boron, and 0.05 zirconium.

7. An intermetallic compound material composed of in atomic percent,about 64.8 nickel. 3.2 chromium, 6.8 cobalt, l.l molybdenum, 19.0aluminum, 4.8 niobium 0.2 carbon, 0.05 boron, and 0.05 zirconium.

8. An intermctallic compound material composed of in atomic percent,about 60.7 nickel, 4.0 chromium, 10.5 cobalt, 0.1 molybdenum, 13.7aluminum, 10.7 titanium, 0.2 carbon. 0.05 boron, and 0.05 zirconium.

9. An intermetallic compound material composed of in atomic percent,about 71.6 nickel, 4.0 chromium, l.l molybdenum, 18.9 aluminum, 2.ltitanium, 2.0 niobium, 0.2 carbon, 0.05 boron, and 0.05 zirconium.

10. An intermctallic compound material composed of in atomic percent,about 64.6 nickel, 3.9 chromium, 7.1 cobalt, 1.0 tungsten, 19.5aluminum, 3.6 tantalum,

0.2 carbon, 0.05 boron, and 0.05 zirconium.

=l =l l=

1. AN INTERMETALLIC COMPOUND MATERIAL COMPOSED OF IN ATOMIC PERCENT,ABOUT 64.M NICKEL, 3.7 CHROMIUM, 6.9 COLBALT, 1.3 MOLYBDENUM, 17.2ALUMINUM, 5.9 TITANIUM, 0.2 CARBON, 0.05 BORON, AND 0.05 ZIRCONIUM. 2.An intermetallic compound material composed of in atomic percent, about64.2 nickel, 3.3 chromium, 7.1 cobalt, 0.8 molybdenum, 0.4 tungsten,19.0 aluminum, 2.3 titanium, 1.3 niobium, 1.3 tantalum, 0.2 carbon, 0.05boron, and 0.05 zirconium.
 3. An intermetallic compound materialcomposed of in atomic percent, about 62.8 nickel, 3.2 chromium, 7.3cobalt, 0.7 molybdenum, 0.4 tungsten, 20.2 aluminum, 1.1 titanium, 2.1niobium, 1.9 tantalum, 0.2 carbon, 0.05 boron, and 0.05 zirconium.
 4. Anintermetallic compound material composed of in atomic percent, about64.5 nickel, 3.4 chromium, 7.2 cobalt, 0.7 molybdenum, 0.5 tungsten,18.0 aluminum, 3.7 titanium, 0.8 niobium, 0.9 tantalum, 0.2 carbon, 0.05boron, and 0.05 zirconium.
 5. An intermetallic compound materialcomposed of in atomic percent, about 61.5 nickel, 5.1 chromium, 7.9cobalt, 1.8 tungsten, 19.9 aluminum, 3.5 tantalum, 0.2 carbon, 0.05boron, and 0.05 zirconium.
 6. An intermetallic compound materialcomposed of in atomic percent, about 62.9 nickel, 2.8 chromium, 6.5cobalt, 1.0 molybdenum, 21.1 aluminum, 5.4 tantalum, 0.2 carbon, 0.05boron, and 0.05 zirconium.
 7. An intermetallic compound materialcomposed of in atomic percent, about 64.8 nickel, 3.2 chromium, 6.8cobalt, 1.1 molybdenum, 19.0 aluminum, 4.8 niobium 0.2 carbon, 0.05boron, and 0.05 zirconium.
 8. An intermetallic compound materialcomposed of in atomic percent, about 60.7 nickel, 4.0 chromium, 10.5cobalt, 0.1 molybdenum, 13.7 aluminum, 10.7 titanium, 0.2 carbon, 0.05boron, and 0.05 zirconium.
 9. An intermetallic compound materialcomposed of in atomic percent, about 71.6 nickel, 4.0 chromium, 1.1molybdenum, 18.9 aluminum, 2.1 titanium, 2.0 niobium, 0.2 carbon, 0.05boron, and 0.05 zirconium.
 10. An intermetallic compound maTerialcomposed of in atomic percent, about 64.6 nickel, 3.9 chromium, 7.1cobalt, 1.0 tungsten, 19.5 aluminum, 3.6 tantalum, 0.2 carbon, 0.05boron, and 0.05 zirconium.